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2003 Volume 20 Issue 9
2003, 20(9): 817-822
Abstract:
The recent research advances in the preparation of linear low density polyethylene(LLDPE) have been reviewed, including the "comonomer effect", the in-situ copolymerization of ethylene and LLDPE synthesized through "chain walking" mechanism using late transition metal catalysts etc. The factors affecting "comonomer effect" were particularly summed up accompanied by a simple explanation.
The recent research advances in the preparation of linear low density polyethylene(LLDPE) have been reviewed, including the "comonomer effect", the in-situ copolymerization of ethylene and LLDPE synthesized through "chain walking" mechanism using late transition metal catalysts etc. The factors affecting "comonomer effect" were particularly summed up accompanied by a simple explanation.
2003, 20(9): 823-828
Abstract:
Bilirubin(H2BR) and di-(2-ethylhexyl) phosphoric acid(HDEHP) were dissolved in chloroform/benzene mixture and partially saponified by ammonia to prepare reversed microemulsions which were characterized by TEM, conductometry and dynamic laser-scattering. The results showed that the mixture of benzene and chloroform in volume ratio of 7:3 was an optimal solvent and ammonia with concentration of 1.00 mol/L was the best saponifier for the formation of microemulsions. The molar ratio of H2BR to HDEHP decreased with the increase in the total concentration of surfactants. The content of H2BR affected greatly the amount of water in microemulsions. The diameter of water pool in microemulsions ranged from 60 nm to 120 nm, which were used to simulate a cell membrane and to produce a new reversed microemulsions containing CaCl2/H2BR/HDEHP. Calcium bilirubinate could be induced and controlled by both surfactants in the system, similar to that of biomineralization process in organism.
Bilirubin(H2BR) and di-(2-ethylhexyl) phosphoric acid(HDEHP) were dissolved in chloroform/benzene mixture and partially saponified by ammonia to prepare reversed microemulsions which were characterized by TEM, conductometry and dynamic laser-scattering. The results showed that the mixture of benzene and chloroform in volume ratio of 7:3 was an optimal solvent and ammonia with concentration of 1.00 mol/L was the best saponifier for the formation of microemulsions. The molar ratio of H2BR to HDEHP decreased with the increase in the total concentration of surfactants. The content of H2BR affected greatly the amount of water in microemulsions. The diameter of water pool in microemulsions ranged from 60 nm to 120 nm, which were used to simulate a cell membrane and to produce a new reversed microemulsions containing CaCl2/H2BR/HDEHP. Calcium bilirubinate could be induced and controlled by both surfactants in the system, similar to that of biomineralization process in organism.
2003, 20(9): 829-832
Abstract:
Alkylation reactions of benzene with 1-hexene catalyzed by ferric chloride in a new ionic liquid system containing triethylamine hydrochloride modified by HCl has been studied. The influences of the constitution of the ionic liquid system, the amount of HCl, temperature and mole ratio of bezene to 1-hexene on the conversion and selectivity of the alkylation reactions have been investigated. It was found that the acidity of this ionic liquid system depends on the constitution of the ionic liquid system and the amount of HCl.The ionic liquid system with x(FeCl3)=66.7% is of no catalytic activity to the reaction without HCl modifying. But the conversion of 1-hexene can reach 100% with the product's monoalkylation selectivity being 100% in 1 h when the ionic liquid system was modified by HCl.
Alkylation reactions of benzene with 1-hexene catalyzed by ferric chloride in a new ionic liquid system containing triethylamine hydrochloride modified by HCl has been studied. The influences of the constitution of the ionic liquid system, the amount of HCl, temperature and mole ratio of bezene to 1-hexene on the conversion and selectivity of the alkylation reactions have been investigated. It was found that the acidity of this ionic liquid system depends on the constitution of the ionic liquid system and the amount of HCl.The ionic liquid system with x(FeCl3)=66.7% is of no catalytic activity to the reaction without HCl modifying. But the conversion of 1-hexene can reach 100% with the product's monoalkylation selectivity being 100% in 1 h when the ionic liquid system was modified by HCl.
2003, 20(9): 833-836
Abstract:
In a Tris buffer solution(pH=7.40), there are an absorption peak at 260 nm for silicotungstic heteropolyacid(SiW) system and independently a fluorescence peak at 350 nm for human serum albumin(HSA) system. When both HSA and SiW solutions are mixed, ion association nanoparticles in size of 50 nm are formed. As a result Rayleigh scattering peak at 470 nm was enhanced considerably and the fluorescence peak at 350 nm was quenched. The Rayleigh scattering spetra and TEM observation revealed that the formation of HSA-SiW nanoparticles and interface formation are main factors that causes the fluorescence quenching and Rayleigh scattering enhancement.
In a Tris buffer solution(pH=7.40), there are an absorption peak at 260 nm for silicotungstic heteropolyacid(SiW) system and independently a fluorescence peak at 350 nm for human serum albumin(HSA) system. When both HSA and SiW solutions are mixed, ion association nanoparticles in size of 50 nm are formed. As a result Rayleigh scattering peak at 470 nm was enhanced considerably and the fluorescence peak at 350 nm was quenched. The Rayleigh scattering spetra and TEM observation revealed that the formation of HSA-SiW nanoparticles and interface formation are main factors that causes the fluorescence quenching and Rayleigh scattering enhancement.
2003, 20(9): 837-840
Abstract:
The electrochemical behavior of dimethoxymethane (DMM) in the H2SO4 solution at the smooth Pt electrode were investigated by cyclovoltammetry. The effects of DMM concentration, H2SO4 concentration and temperature on the electrochemical behavior of DMM and its mechanism were studied.
The electrochemical behavior of dimethoxymethane (DMM) in the H2SO4 solution at the smooth Pt electrode were investigated by cyclovoltammetry. The effects of DMM concentration, H2SO4 concentration and temperature on the electrochemical behavior of DMM and its mechanism were studied.
2003, 20(9): 841-844
Abstract:
Triphenyltin(Ⅳ) dithiomorpholinocarbamate Ph3SnS2CN(C4H8O) has been synthesized by reacting triphenyltin chloride with sodium dithiomorpholinocarbamate and characterized by elemental analysis, UV, IR and 1H NMR. The crystal of the compound is monoclinic with space group P2(1)/c, a=1.223 6(5) nm, b=1.167 0(5) nm, c=1.579 1(6) nm, β=99.061(5)°, Z=4, V=2.226 9(15) nm3, Dc=1.528 g/cm3, μ=1.348 mm-1, R=0.026 2, wR=0.061 5. The structure shows a distorted trigonal bidendate and five-coordinated configuration to the central tin atom. The in vitro antitumor activity of the complex against the human tumor cell lines, MCF-7, a mammary tumor, is examined. The ID 50(μg/L) value is 850.
Triphenyltin(Ⅳ) dithiomorpholinocarbamate Ph3SnS2CN(C4H8O) has been synthesized by reacting triphenyltin chloride with sodium dithiomorpholinocarbamate and characterized by elemental analysis, UV, IR and 1H NMR. The crystal of the compound is monoclinic with space group P2(1)/c, a=1.223 6(5) nm, b=1.167 0(5) nm, c=1.579 1(6) nm, β=99.061(5)°, Z=4, V=2.226 9(15) nm3, Dc=1.528 g/cm3, μ=1.348 mm-1, R=0.026 2, wR=0.061 5. The structure shows a distorted trigonal bidendate and five-coordinated configuration to the central tin atom. The in vitro antitumor activity of the complex against the human tumor cell lines, MCF-7, a mammary tumor, is examined. The ID 50(μg/L) value is 850.
2003, 20(9): 845-848
Abstract:
The ion transfer number is introduced in the formula describing the relationship between ionic limiting molar conductivity and ionic concentration based on mode coupling theory(MCT). A series of calculated for the ionic limiting molar conductivity are present. The ionic limiting molar conductivities of seven lithium salts in two single organic solvents and two mixed solvents are calculated. The results are in good agreement with the literature's results which are calculated either from transport number obtained by empirical formula or from transport number obtained by electrochemiscal experiments.
The ion transfer number is introduced in the formula describing the relationship between ionic limiting molar conductivity and ionic concentration based on mode coupling theory(MCT). A series of calculated for the ionic limiting molar conductivity are present. The ionic limiting molar conductivities of seven lithium salts in two single organic solvents and two mixed solvents are calculated. The results are in good agreement with the literature's results which are calculated either from transport number obtained by empirical formula or from transport number obtained by electrochemiscal experiments.
2003, 20(9): 849-852
Abstract:
The supported catalyst Au/TiO2 was prepared by deposition-precipitation method. Chemsorbility of the catalyst was studied by in situ IR and TPD techniques and activity of the catalyst was tested in a micro-reactor. The results revealed that propylene is chemisorbed on Lewis acid sites Tin+ on the surface of Au/TiO2 through C-C bond and newly formed propylene oxide is chemisorbed on Tin+ through the oxygen of its epoxy ring. The selectivity of propylene oxide in propylene epoxidation over Au/TiO2 is 93% and conversion of propylene is 0.76%. Au nano-particles adsorb H2 and O2 and transform them into peroxide species, which diffuse to Ti site, leading to the formation of propylene oxide.
The supported catalyst Au/TiO2 was prepared by deposition-precipitation method. Chemsorbility of the catalyst was studied by in situ IR and TPD techniques and activity of the catalyst was tested in a micro-reactor. The results revealed that propylene is chemisorbed on Lewis acid sites Tin+ on the surface of Au/TiO2 through C-C bond and newly formed propylene oxide is chemisorbed on Tin+ through the oxygen of its epoxy ring. The selectivity of propylene oxide in propylene epoxidation over Au/TiO2 is 93% and conversion of propylene is 0.76%. Au nano-particles adsorb H2 and O2 and transform them into peroxide species, which diffuse to Ti site, leading to the formation of propylene oxide.
2003, 20(9): 853-856
Abstract:
The solvent-free transesterification of ethyl decanoate with 1-hexanol has been carried out by cata-lysis through direct mixing of powdered lipase, Rhizopus arrbizus or Candida rugosa, with carrier and substrates. The results showed that water content, amount of silica gel and reaction time affected the rate or yield of the reaction. For a mixture of 25 mg of silica gel, 5 mg of Rhizopus arrbizus lipase powder, 18 μL of 50 mmol/L phosphate buffer(pH=7.0) or 10 mg of Candida rugosa lipase powder, 15 μL of buffer, the both lipases catalyzed reactions proceed readily, and after 20 h, yield greater than 90% could be achieved. The lipase mixed with silica gel can be reused many times.
The solvent-free transesterification of ethyl decanoate with 1-hexanol has been carried out by cata-lysis through direct mixing of powdered lipase, Rhizopus arrbizus or Candida rugosa, with carrier and substrates. The results showed that water content, amount of silica gel and reaction time affected the rate or yield of the reaction. For a mixture of 25 mg of silica gel, 5 mg of Rhizopus arrbizus lipase powder, 18 μL of 50 mmol/L phosphate buffer(pH=7.0) or 10 mg of Candida rugosa lipase powder, 15 μL of buffer, the both lipases catalyzed reactions proceed readily, and after 20 h, yield greater than 90% could be achieved. The lipase mixed with silica gel can be reused many times.
2003, 20(9): 857-861
Abstract:
Four polyoxometalate particles H3MPMo10V2O40·xH2O(M=Co2+,Ni2+,Cu2+,Zn2+) were synthesized by solid-state reaction at room temperature. Their structures, particle sizes, thermal properties and surface properties were investigated by IR, UV, XRD, TEM, TG-DTA and TPR techniques. The results show that these four polyoxometate particles have Keggin structure with size being 32~42 nm. The thermal stability of the polyoxometalates appeared decreased, but surface activity increased significantly, when they are in nanoparticles form.
Four polyoxometalate particles H3MPMo10V2O40·xH2O(M=Co2+,Ni2+,Cu2+,Zn2+) were synthesized by solid-state reaction at room temperature. Their structures, particle sizes, thermal properties and surface properties were investigated by IR, UV, XRD, TEM, TG-DTA and TPR techniques. The results show that these four polyoxometate particles have Keggin structure with size being 32~42 nm. The thermal stability of the polyoxometalates appeared decreased, but surface activity increased significantly, when they are in nanoparticles form.
2003, 20(9): 862-866
Abstract:
Three novel malononitrile derivatives have been synthesized by the solid state reaction at room temperature. The reactions are carried out for 0.5 h with yields all beyond 93%. The compounds have been characterized by IR、UV、1H NMR and elemental analysis. The structure of the compound 3 is determined by X-ray diffraction analysis. The single-and double-photon fluorescence spectra of the compounds 2 and 3 are discussed. The results show that single-photon and double-photon fluorescences have similar solvent effect.
Three novel malononitrile derivatives have been synthesized by the solid state reaction at room temperature. The reactions are carried out for 0.5 h with yields all beyond 93%. The compounds have been characterized by IR、UV、1H NMR and elemental analysis. The structure of the compound 3 is determined by X-ray diffraction analysis. The single-and double-photon fluorescence spectra of the compounds 2 and 3 are discussed. The results show that single-photon and double-photon fluorescences have similar solvent effect.
2003, 20(9): 867-870
Abstract:
Poly(allylamine)-silica composite(PAA-silica composite) was synthesized by grafting chloropropyltrichloro-silane(CPTCS-silica) gel onto PAA polymer in the solution. The PAA-silica composite with amino group content of 1.75 mmol/g was obtained by reacting 75 g CPTCS-silica with 185 g PAA-15 in 100 mL methanol. The result shows that PAA-silica composite could be used as an adsorbent for metal ions, which has an adsorption capacity of 0.85 mmol/g for Cu(Ⅱ) at pH=3.5 and of 0.53 mmol/g for Pb(Ⅱ) at pH=4.0 at 25℃, respectively. The structures and properties of silica gel, CPTCS-silica and PAA-silica composites were characterized by the FTIR spectra and angles of contact.
Poly(allylamine)-silica composite(PAA-silica composite) was synthesized by grafting chloropropyltrichloro-silane(CPTCS-silica) gel onto PAA polymer in the solution. The PAA-silica composite with amino group content of 1.75 mmol/g was obtained by reacting 75 g CPTCS-silica with 185 g PAA-15 in 100 mL methanol. The result shows that PAA-silica composite could be used as an adsorbent for metal ions, which has an adsorption capacity of 0.85 mmol/g for Cu(Ⅱ) at pH=3.5 and of 0.53 mmol/g for Pb(Ⅱ) at pH=4.0 at 25℃, respectively. The structures and properties of silica gel, CPTCS-silica and PAA-silica composites were characterized by the FTIR spectra and angles of contact.
2003, 20(9): 871-874
Abstract:
The Fe2+ was extracted from pyrite cinder by reduction roasting method and transformed into FeSO4 as a precursor to make α-FeOOH. The crystal nucleus of α-FeOOH was prepared in a neutral solution (pH:6~7) of FeSO4(0.15~0.25 mol/L) and Na2CO3(n(Na2CO3):n(FeSO4)=1:1). In order to maintain a proper oxidizing rate of Fe2+ the pH value of the solution has been acicular in the range of 4~5 by dropping Na2CO3 solution. A uniform needle crystal of α-FeOOH has been obtained with width 30~40 nm and length about 250 nm.
The Fe2+ was extracted from pyrite cinder by reduction roasting method and transformed into FeSO4 as a precursor to make α-FeOOH. The crystal nucleus of α-FeOOH was prepared in a neutral solution (pH:6~7) of FeSO4(0.15~0.25 mol/L) and Na2CO3(n(Na2CO3):n(FeSO4)=1:1). In order to maintain a proper oxidizing rate of Fe2+ the pH value of the solution has been acicular in the range of 4~5 by dropping Na2CO3 solution. A uniform needle crystal of α-FeOOH has been obtained with width 30~40 nm and length about 250 nm.
2003, 20(9): 875-878
Abstract:
Polyacrylate sodium(PAANa) and poly(acrylate sodium-acrylamide) were synthesized by inverse suspension polymerization and their anti-electrolyte properties were investigated. Copolymerisation of AANa with AM could lead to increasing the anti-electrolyle property of copolymer due the presence of synergistic action between the different hydrophillic groups of polymer components. The copolymer with mol fraction of AM to (AM+AANa)=7.42% showed the best liquid absovability. In the case of aqueous NaCl solution the liquid absorption Q5/3 is inversly proportional to the NaCl concentration. In addition the kinetics behavior of PAANa and P((AANa+AM) resins at initial swelling stage was found to be fitted with first order kinetic reaction and the kinetic constant was given.
Polyacrylate sodium(PAANa) and poly(acrylate sodium-acrylamide) were synthesized by inverse suspension polymerization and their anti-electrolyte properties were investigated. Copolymerisation of AANa with AM could lead to increasing the anti-electrolyle property of copolymer due the presence of synergistic action between the different hydrophillic groups of polymer components. The copolymer with mol fraction of AM to (AM+AANa)=7.42% showed the best liquid absovability. In the case of aqueous NaCl solution the liquid absorption Q5/3 is inversly proportional to the NaCl concentration. In addition the kinetics behavior of PAANa and P((AANa+AM) resins at initial swelling stage was found to be fitted with first order kinetic reaction and the kinetic constant was given.
2003, 20(9): 879-882
Abstract:
Some metal oxides, organic and inorganic salts were studied as catalyst for synthesis of aliphatic carbonic ester by alcoholysis of urea. It is found that ZnO has higher catalytic activity in the catalysts tested with diisoamyl carbonate yield 58.3%~76.3%, when reaction is carried out at 160~200℃ for 8 h, the molar ratio of isoamyl alcohol to urea and mass fraction of catalyst are 3.3 and 0.85% respectively.
Some metal oxides, organic and inorganic salts were studied as catalyst for synthesis of aliphatic carbonic ester by alcoholysis of urea. It is found that ZnO has higher catalytic activity in the catalysts tested with diisoamyl carbonate yield 58.3%~76.3%, when reaction is carried out at 160~200℃ for 8 h, the molar ratio of isoamyl alcohol to urea and mass fraction of catalyst are 3.3 and 0.85% respectively.
2003, 20(9): 883-887
Abstract:
In the medium of pH 3.5~6.0, La(Ⅲ) and Evans blue(EB) react with aminoglycoside antibio-tics, such as neomycin sulfate(NEO), kanamycin sulfate(KANA), gentamycin sulfate(GEN) and tobramycin sulfate(TOB), to form ternary blue ion association complexes with an obvious absorption peak and an fading peak. The maximum absorption wavelengths are between 668 nm and 674 nm, the linear ranges in 0~1.2×10-5 g/mL to 0~1.40×10-5 g/mL, with molar absorptivities(ε) between 3.10×104 and 6.17×104 L/(mol·cm). The maximum fading wavelengths are in between 614 nm and 620 nm, and the linear ranges in 0~9.0×10-6 g/mL to 0~1.7×10-5 g/mL, with molar absorptivities(ε) between 4.33×104 and 1.04×105 L/(mol·cm). Their sensitivity is much higher when the positive minus wavelengths overlapping absorption spectrometry is used to determine the concentrations of aminoglycoside antibiotics. The reaction conditions, the important properties in analytical chemistry and the compound ratio of ternary ion association complexes(La:EB:GEN=1:2:3) have been discussed. The method has been applied to determining the content of the commerce aminoglycoside antibiotics with satisfactory results.
In the medium of pH 3.5~6.0, La(Ⅲ) and Evans blue(EB) react with aminoglycoside antibio-tics, such as neomycin sulfate(NEO), kanamycin sulfate(KANA), gentamycin sulfate(GEN) and tobramycin sulfate(TOB), to form ternary blue ion association complexes with an obvious absorption peak and an fading peak. The maximum absorption wavelengths are between 668 nm and 674 nm, the linear ranges in 0~1.2×10-5 g/mL to 0~1.40×10-5 g/mL, with molar absorptivities(ε) between 3.10×104 and 6.17×104 L/(mol·cm). The maximum fading wavelengths are in between 614 nm and 620 nm, and the linear ranges in 0~9.0×10-6 g/mL to 0~1.7×10-5 g/mL, with molar absorptivities(ε) between 4.33×104 and 1.04×105 L/(mol·cm). Their sensitivity is much higher when the positive minus wavelengths overlapping absorption spectrometry is used to determine the concentrations of aminoglycoside antibiotics. The reaction conditions, the important properties in analytical chemistry and the compound ratio of ternary ion association complexes(La:EB:GEN=1:2:3) have been discussed. The method has been applied to determining the content of the commerce aminoglycoside antibiotics with satisfactory results.
2003, 20(9): 888-892
Abstract:
The novel catalysts of TiCl4-acac-Co(acac)2, TiCl4-Co(acac)2 and TiCl4-acac supported on SiO2-MgCl2 carrier(Ti-Co combined catalyst) were prepared. They catalyze polymerimerization of ethylene giving branched polyethylene when Et2AlCl was used as a cocatalyst. The polymerization products have low melting point, low crystallinity and high degree of branching as evaluated by FTIR, DSC and 13C NMR spectrum. The results of 13C NMR suggested more than 55.0% of the polyethylene contain long branch chain(n≥6). Experimental results showed that the Ti-Co combined catalyst exhibites an excellent catalytic property for oligomerization and in situ copolymerization of ethylene.
The novel catalysts of TiCl4-acac-Co(acac)2, TiCl4-Co(acac)2 and TiCl4-acac supported on SiO2-MgCl2 carrier(Ti-Co combined catalyst) were prepared. They catalyze polymerimerization of ethylene giving branched polyethylene when Et2AlCl was used as a cocatalyst. The polymerization products have low melting point, low crystallinity and high degree of branching as evaluated by FTIR, DSC and 13C NMR spectrum. The results of 13C NMR suggested more than 55.0% of the polyethylene contain long branch chain(n≥6). Experimental results showed that the Ti-Co combined catalyst exhibites an excellent catalytic property for oligomerization and in situ copolymerization of ethylene.
2003, 20(9): 893-897
Abstract:
Water soluble photosensitive quaternary ammonium salts-containing acrylic phenolic resins(AQPR) were synthesized by reaction of epoxy phenolic resin with different tertiary amine hydrohalide salts to form different quaternary ammonium salt groups. Conversion, photosensitivity and thermal decomposition of the products were compared in order to find a suitable water developable, photosensitive solder mask. The results showed that with regard to reactivity TEA > TMA > DMA > TENA > TBA; HCl > HBr > HI. The resin obtained from TMA exhibited the highest photosensitivity, whereas those from TEA and TMA showed the best water solubility. During thermal treatment of the products containing both quaternary ammonium salt groups and epoxy groups at 160℃ for 0.5 h, besides partial decomposition, water insoluble component was formed, whereas the halide ions and epoxy groups of the thermal decomposition product diminished. This implies that at the thermal decomposition not only the halide ions diminished, but also crosslinkage were formed.
Water soluble photosensitive quaternary ammonium salts-containing acrylic phenolic resins(AQPR) were synthesized by reaction of epoxy phenolic resin with different tertiary amine hydrohalide salts to form different quaternary ammonium salt groups. Conversion, photosensitivity and thermal decomposition of the products were compared in order to find a suitable water developable, photosensitive solder mask. The results showed that with regard to reactivity TEA > TMA > DMA > TENA > TBA; HCl > HBr > HI. The resin obtained from TMA exhibited the highest photosensitivity, whereas those from TEA and TMA showed the best water solubility. During thermal treatment of the products containing both quaternary ammonium salt groups and epoxy groups at 160℃ for 0.5 h, besides partial decomposition, water insoluble component was formed, whereas the halide ions and epoxy groups of the thermal decomposition product diminished. This implies that at the thermal decomposition not only the halide ions diminished, but also crosslinkage were formed.
2003, 20(9): 898-902
Abstract:
The catalytcal behavior of a series catalysts, including Lewis acid and base, titanates and tin compounds in transesterification of phenol(PhOH) and dimethylcarbonate(DMC) have been investigated. It is found that Pb(Ac0)2·3H2O and Ti(OBu)4 exihibites higher activities, and the highest catalytic activity among above mentioned catalysts is Bu2SnO. The effects of the ratio of reactants, amount of catalyst, reaction temperature and reaction time on the reaction were examined. It is found that at molar ratio of DMC:PhOH:Bu2SnO=2.0:1.0:0.03, 175℃ and 14 h the conversion of phenol was 43.0%, with selectivity for methylphenyl carbonate, and diphenyl carbonate being 96.8% and 3.2%, respectively.
The catalytcal behavior of a series catalysts, including Lewis acid and base, titanates and tin compounds in transesterification of phenol(PhOH) and dimethylcarbonate(DMC) have been investigated. It is found that Pb(Ac0)2·3H2O and Ti(OBu)4 exihibites higher activities, and the highest catalytic activity among above mentioned catalysts is Bu2SnO. The effects of the ratio of reactants, amount of catalyst, reaction temperature and reaction time on the reaction were examined. It is found that at molar ratio of DMC:PhOH:Bu2SnO=2.0:1.0:0.03, 175℃ and 14 h the conversion of phenol was 43.0%, with selectivity for methylphenyl carbonate, and diphenyl carbonate being 96.8% and 3.2%, respectively.
2003, 20(9): 903-907
Abstract:
The synergistic extractions of Pr(Ⅲ) with 1,9-bis(1'-phenyl-3'-methyl-5'-oxopyrazole-4'-yl)-1,9-nonanedione(H2A) and neutral nitrogenous bidentate extractants(B), such as 1,10-phenanthroline(Phen), 2,9-dimethyl-4,7-diphenyl-phenanthroline(DDPhen), 5-nitro-phenanthroline(NPhen), 2,2'-bipyridyl(2,2'-bipy) and 4,4'-bipyridyl(4,4'-bipy), have been investigated. The extraction complex was shown to be PrA·HA·B. The extraction constants were determined. The solid extracted species PrHA·NPhen was obtained and confirmed by elemental analysis, IR, UV, TG and DTA.
The synergistic extractions of Pr(Ⅲ) with 1,9-bis(1'-phenyl-3'-methyl-5'-oxopyrazole-4'-yl)-1,9-nonanedione(H2A) and neutral nitrogenous bidentate extractants(B), such as 1,10-phenanthroline(Phen), 2,9-dimethyl-4,7-diphenyl-phenanthroline(DDPhen), 5-nitro-phenanthroline(NPhen), 2,2'-bipyridyl(2,2'-bipy) and 4,4'-bipyridyl(4,4'-bipy), have been investigated. The extraction complex was shown to be PrA·HA·B. The extraction constants were determined. The solid extracted species PrHA·NPhen was obtained and confirmed by elemental analysis, IR, UV, TG and DTA.
2003, 20(9): 908-910
Abstract:
The activity of candida Sp lipase(CSL) in catalytic hydrolysis of olive oil has been investigated in W/O reversed micelle of AEOT/isooctane/water system and compared with that of AOT/isooctane/water system. The results indicated that the activity of lipase in AEOT/isooctane reversed micelles was about 2 times that in AOT/isooctane reversed micelles in the optimum water content(W0=12) and pH=7.2, and the maximum hydrolysis rate(Vmax) increased nearly 3 times.
The activity of candida Sp lipase(CSL) in catalytic hydrolysis of olive oil has been investigated in W/O reversed micelle of AEOT/isooctane/water system and compared with that of AOT/isooctane/water system. The results indicated that the activity of lipase in AEOT/isooctane reversed micelles was about 2 times that in AOT/isooctane reversed micelles in the optimum water content(W0=12) and pH=7.2, and the maximum hydrolysis rate(Vmax) increased nearly 3 times.
2003, 20(9): 911-913
Abstract:
N-(4-Hydroxyphenylmethylene)-1-naphthylamine was synthesized by the solid phase reaction of 1-naphthylamine and 4-hydroxybenzaldehyde at room temperature. The reaction was completed in 15 min in yield of 95%. The product was characterized by elemental analysis, IR, X-ray powder diffractometry and 1H NMR. The crystal as determined by X-ray single crystal diffractometry belongs to monoclinic system with space group P21/c, a=1.004 9(2), b=1.047 3(2), c=1.200 2(2) nm, β=92.60(3)°, V=1.261 8(4) nm3, Dc=1.302 g/cm3, Z=4, F(000)=528, μ=0.081 mm-1, R=0.0375, wR=0.106 2, S=1.024.
N-(4-Hydroxyphenylmethylene)-1-naphthylamine was synthesized by the solid phase reaction of 1-naphthylamine and 4-hydroxybenzaldehyde at room temperature. The reaction was completed in 15 min in yield of 95%. The product was characterized by elemental analysis, IR, X-ray powder diffractometry and 1H NMR. The crystal as determined by X-ray single crystal diffractometry belongs to monoclinic system with space group P21/c, a=1.004 9(2), b=1.047 3(2), c=1.200 2(2) nm, β=92.60(3)°, V=1.261 8(4) nm3, Dc=1.302 g/cm3, Z=4, F(000)=528, μ=0.081 mm-1, R=0.0375, wR=0.106 2, S=1.024.
2003, 20(9): 914-916
Abstract:
Triethanolammonium tetrachloronickelate was synhesized by a solid state reaction of triethanolamine hydrochloride with anhydrous nickel chloride. The compound undergoes a reversible thermochromism phase transition at ca.152℃. UV-visible, near-IR, IR spectra and elemental analysis results confirmed the structure of the product. It was deduced that thermochromism of the product is caused by the structural phase transition of the complex ion, NiCl42-. The enthalpy change of phase transition for the product was 61.0 kJ/mol determinated by DSC.
Triethanolammonium tetrachloronickelate was synhesized by a solid state reaction of triethanolamine hydrochloride with anhydrous nickel chloride. The compound undergoes a reversible thermochromism phase transition at ca.152℃. UV-visible, near-IR, IR spectra and elemental analysis results confirmed the structure of the product. It was deduced that thermochromism of the product is caused by the structural phase transition of the complex ion, NiCl42-. The enthalpy change of phase transition for the product was 61.0 kJ/mol determinated by DSC.
2003, 20(9): 917-918
Abstract:
N-Methylmorpholine was synthesized by alkylation of morpholine with chloromethane in sodium hydroxide solution. The influences of reaction temperature, reaction time and molar ratio of reactants on the yield of the reaction were examined. The optimum reaction conditions are as follows:reaction temperature 35℃, time 5 h, n(morpholine):n(monochloromethane)=1:1.1, n(morpholine):n(sodium hydroxide)=1:1.2, yield of N-methylmorpholine 85%, purity 98%.
N-Methylmorpholine was synthesized by alkylation of morpholine with chloromethane in sodium hydroxide solution. The influences of reaction temperature, reaction time and molar ratio of reactants on the yield of the reaction were examined. The optimum reaction conditions are as follows:reaction temperature 35℃, time 5 h, n(morpholine):n(monochloromethane)=1:1.1, n(morpholine):n(sodium hydroxide)=1:1.2, yield of N-methylmorpholine 85%, purity 98%.
